Social science data sets have gown exponentially both in size and number over the last ten years. However, easy access to these data sets by social scientists has lagged considerably. The objective of this research is to empower social scientists with the ability to search a wide universe of archived social science data sets, select data appropriate to their research objectives, and acquire files and documentation as soon as they are selected. The data sets to be made available on-line are those comprising the public data archives at Sociometrics Corporation: the Data Archive on Adolescent Pregnancy and Pregnancy Prevention, the American Family Data Archive, the AIDS/STD Data Archive, the Maternal Drug Abuse Archive, the Data Archive of Social Research on Aging, and the Disability Data Archive. Over 200 premier data sets--processed and documented in standard fashion--are currently available from these archives. By late 1995, the launch date for the proposed on-line data center, over 350 data sets will be available. Two access modes will be investigated: (1) SOCIONET-DIRECT--direct access to data, documentation, and software contained on a set of CD-ROMs housed at the user's site, either on a single microcomputer or on a LAN (local Area Network); and (2) SOCIONET-REMOTE--on-line, remote access to the SOCIONET data, documentation, and software housed at Sociometrics Corporation. SOCIONET will be accompanied by innovative search and retrieval software that allows users to browse through the contents of the various data archives at both the study and variable levels. Phase I will produce designs and prototype systems that demonstrate the feasibility of establishing and operating SOCIONET.